1. Field of the Invention
This invention relates to theft-thwarting devices for preventing the loss of shopping carts from shopping stores. The invention disables operation of the front wheels of the cart, and keeps the cart from being pushed off the market premises or out of the parking lot once the front wheels are disabled. Other new theft-defeating features are incorporated in this invention.
2. Description of related Art
Millions of dollars are lost each year by grocery stores and shopping markets as a result of shopping cart theft. The expenses associated with shopping cart theft include costs for cart replacement, retrieval of carts taken off the premises, and rehabilitation of the carts once they are returned.
The prior art is replete with devices intended to prevent shopping cart theft, but none before applicants' invention have achieved such a result in the manner suggested by applicants. For example, U.S. Pat. No. 3,717,225 to Rashbaum (1973) discloses a piston rod and wheel lock device which includes a frame mounted actuator that locks one of the wheels of the cart. It does not eliminate the potential for the use of one bank of cart wheels rotating by lifting the disabled wheel from the contact with the ground. U.S. Pat. No. 5,315,290 to Moreno (1994) discloses an electronic wheel lock device, which also fails to eliminate the possibility of leaning the cart to the side of the still active wheels, and thus prevent cart theft. U.S. Pat. No. 4,242,668 to Herzog (1980) discloses a collapsible sub frame causing the wheels to swing out of operative position. This device immobilizes the front wheels of the cart, but does not eliminate the possibility the cart can be leaned back, and rolled away using the rear wheels of the cart. U.S. Pat. No. 5,357,182 to Wolfe et al. (1994) discloses a braked wheel device. This device also fails to eliminate the possibility of leaning the cart to the side of the still active wheels once the cart has left the boundary of the parking lot. U.S. Pat. No. 4,524,985 to Drake (1985) discloses an arrest device for a wheeled cart, which relies on a hooking device in the parking lot, but does not appear to eliminate the possibility that the cart could be leaned to one side to avoid the hooking device. Similarly, U.S. Pat. No. 5,576,691 to Coaklet et al. (1996) discloses another form of a wheel locking device that also fails to prevent the removal of the cart by a user who can simply tip the cart onto its back wheels and roll the cart away. U.S. Pat. No. 4,577,880 to Bianco (1986) discloses still another form of a wheel locking device that fails to eliminate the removal of the cart by simply tipping the cart on to the back wheels and rolling the cart away. U.S. Pat. No. 4,772,880 to Goldstein (1988) discloses another form of the wheel locking device, disabling only one of the front wheels. U.S. Pat. No. 5,194,844 to Zelda (1993) discloses a proximity wheel locking mechanism. This device also fails to eliminate the removal of the cart by simply tipping the cart on to the back wheels and rolling the cart away. U.S. Pat. No. 4,591,175 to Upton (1986) discloses a magnetic wheel locking mechanism. This device also fails to eliminate the removal of the cart by simply tipping the cart on to the back wheels and rolling the cart away.
Many of the devices disclosed by these patents demonstrate that disabling only one wheel of a shopping cart is insufficient to completely immobilize the cart, for even if one wheel is disabled, the person removing the cart can continue to push the cart with sufficient force to override the traction of the locked wheel. Moreover, a shopping cart of the Herzog design, in which the two wheels of the front wheel assembly were disabled by allowing the sub frame of the cart to collapse around the front wheel assembly, failed to prevent the leaning of the cart backwards over, and rolling it away on, its rear wheels.
Not one of these previously known devices totally prevents forward motion of the cart. If one wheel is locked, a person intent on removing the cart from the premises can exert enough force to overcome the friction of the locked wheel. If two wheels are disabled, as is taught by the Herzog patent, the cart can still be maneuvered by tilting the cart so that it can still be rolled away.
In U.S. Pat. No. 6,271,755 to Prather et al., there is disclosed a theft-thwarting mechanism for use with a shopping cart for preventing removal of the cart from the premises of a market. Also known is U.S. Pat. No. 6,054,923 to Prather et al. which discloses a shopping cart that includes a disabling mechanism that renders the cart's swivel wheels inoperative upon actuation of the disabling signal.
The object of these inventions was to make it nearly impossible for a person having the intent to remove the cart from the store's premises by rolling it away. In fact, tests performed by applicants have shown that cart losses due to theft, during a six-month test period, were virtually non-existent. However, various drawbacks and difficulties have since been noted, which the present invention seeks to cure. The present invention is drawn to improvements over the previously presented subject matter, and incorporates additional shopping cart theft thwarting features.
For example, in the past, the cover for the front wheel suspension assembly was easily removable just by removing the fasteners that secured the cover to the suspension assembly. The present invention proposes a solution. In the past, often after repeatedly resetting the cart disabling mechanism, the reset wand failed to properly engage the reset screw associated with the disabled mechanism and resetting was prevented. The present invention provides a novel solution to this difficulty. In the past, various attempts have been made to remove the wheels attached to the front wheel suspension assembly. The present invention offers a solution to this problem.